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Principal forest dieback episodes in Northern Hardwoods: development of numeric indices of areal extent and severity
1997
Auclair, A.N.D. (Science and Policy Associates Inc., Washington, DC (USA).) | Eglinton, P.D. | Minnemeyer, S.L.
Tree bark as a bioindicator of air pollution in Navarra, Spain
1997
Santamaria, J.M. (Navarra Univ., Pamplona (Spain). Dept. of Chemistry and Soil Science) | Martin, A.
Monitoring nitrogen pollution from sugarcane runoff using (15)N analysis
1997
Lindau, C.W. (Louisiana State Univ., Baton Rouge, LA (USA). Nuclear Science Center, Wetland Biogeochemistry Inst.) | Delaune, R.D. | Alford, D.P.
Pollution prevention in the paints and coatings industry
1997
Joseph, Ron
Analyzing nonpoint source water pollution problems
1997
Favero, Philip
Water pollution IV
1997
Rajar, R (Rudi) | Brebbia, C. A.
Himalayan microbial diversity
1997
Sati, S. C. | Saxena, J. (Jitendra) | Dubey, R. C.
The interactions between sediments and water
1997
Evans, R. Douglas | Wisniewski, Joe | Wisniewski, Jan R.
The description, assessment and meaning of vertical fluxes of matter within ecotypes - a systematic consideration Полный текст
1997
Dämmgen, Ulrich | Grünhage, Ludger | Jäger, Hans-Jürgen
Direct aqueous derivation and gas chromatographic analysis of halogenated lower carboxylates in environmental samples
1997
Ozawa, H. (Nagano-ken. Research Inst. for Health and Pollution (Japan))
Analytical method for hydrophilic polar environmental pollutants was studied. Among these pollutants, the halogenated lower carboxylates were the target compounds of this investigation. A novel but simple derivatization method necessary for sample preparation for instrumental analysis was developed. The new derivatization method for the carboxylates is not a conventional chemical reaction in non-aqueous solvent following isolation from the environmental samples but rather, a direct aqueous reaction ; direct conversion of the carboxylates to amides using a carbodiimide in dilute aqueous solution. Halogenoanilines were selectively used with dicyclohexylcarbodiimide (DCC) under acidic conditions at room temperature to form the anilide derivatives. Moreover, this reaction proceeds while mixing the sample water, DCC, a halogenoaniline, and small volume of extracting solvent. Thus, for the first time, simultaneous derivatization of the carboxylates and extraction of the products into solvent was achieved. Based on the results, simple and practical determination methods by gas chromatography were developed for traces of these carboxylates in environmental samples and the proposed methods were applied to some real samples. Such analytical derivatization methods for carboxylates are useful and noteworthy because they can form C-N bonds in aqueous media under mild conditions with carbodiimides and N atoms of amino and other compounds.
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